Having issues with with LiveUpdate on the server not running:

Error: LiveUpdate encountered one or more errors. Return code = 4

You need to uninstall and reinstall Symantec LiveUpdate
This was taken from Symantecs website... proceed with all due caution, your results may differ.

To uninstall and reinstall LiveUpdate:

1. In Windows Explorer make a back-up copy of the following file:
   C:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdate\Product.Inventory.LiveUpdate
   WARNING: It is important to follow this step in order to avoid having to register SEPM or SEP with LiveUpdate.
2. Click Start > Settings > Control Panel.
3. Click Add or Remove Programs.
4. Click LiveUpdate.
5. Click Change/Remove.
6. Follow the on-screen instructions to uninstall LiveUpdate.
7. In Windows Explorer, delete the following folders if they are present:
   C:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdate
   C:\Program Files\Symantec\LiveUpdate
8. Install LiveUpdate using LUSETUP.EXE located in the SEP installation files, in the following folder:
   ...\SEPM\LUSETUP.EXE
9. Browse to:
   C:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdate\Product.Inventory.LiveUpdate
   and replace the newly created Product.Inventory.LiveUpdate file with the file you backed-up in step 1.\

I did all the above and then ran LUALL.exe from the Liveupdate directory under Program Files.
This took more than 30 minutes to run the first time.
There still seemed to be issues with the LiveUpdate in SEPM and when running LUALL.exe manually.
A REBOOT seemed to fix this.

Note: If you did not back-up the Product.Inventory.LiveUpdate file before deleting the LiveUpdate folder you must register SEPM or SEP with LiveUpdate for it to update correctly.

To register SEPM with LiveUpdate:

1. Click Start, then Run.
2. Type cmd, then click OK. This will bring up a command prompt.
3. At the command prompt type cd and the path to lucatalog.exe. By default the command would be:
   cd C:\Program Files\Symantec\Symantec Endpoint Protection Manager\bin
4. Type lucatalog.exe -update

To register the SEP Client with LiveUpdate:

1. Click Start > Settings > Control Panel.
2. Click Add or Remove Programs.
3. Click Symantec Endpoint Protection.
4. Click Change.
5. Click Next, select Repair, and click Next again.
6. Click Install.
7. Click Finish.